Industrial furnace

ABSTRACT

An industrial furnace has at least one furnace chamber and at least two hollow heat-exchange walls each located at and proximal to one lateral side of the furnace chamber so as to exchange heat with the same. At least two regenerators are provided each of which communicates with one of the heat-exchange walls and means is provided for alternately feeding air and flue gas to these regenerators.

Uited States atent n 1 Jakobi et a1.

[54] INDUSTRIAL FURNACE [75] Inventors: Wilhelm Jakohi; Ernst Kumper,

both of Essen; Hans Wagner, Kettwig, all of Germany Heinrich Koppers G.m.b.11., Essen, Germany Filed: Mar. 10, 1971 Appl. No.: 123,188

[73] Assignee:

[30] Foreign Application Priority Data Mar. 10, 1970 Germany ..P 20 11 261.2

US. Cl ..263/l5 R, 202/142, 202/143 Int. Cl. ..F27d 17/00, ClOb 5/14, C101) 5/16 Field of Search.....263/15 R; 202/137, 138, 139,

n 1 3,723,05 I451 Mar. 27, 1973 [56] References Cited UNITED STATES PATENTS 1,257,649 2/1918 Steere ..263/15 R 1,999,514 4/1935 Mueller ..202/143 X 1,613,068 1/1927 Ackeren ..202/143 1,635,679 7/1927 Kus ..202/l43 Primary Examiner-John J. Camby AttorneyMichael S. Striker [57] ABSTRACT An industrial furnace has at least one furnace chamber and at least two hollow heat-exchange walls each located at and proximal to one lateral side of the furnace chamber so as to exchange heat with the same. At least two regenerators are provided each of which communicates with one of the heat-exchange walls and means is provided for alternately feeding air and flue gas to these regenerators.

3 Claims, 3 Drawing Figures PATENTEUHARZYISB 3 7 3,954

SHEET 1 BF 3 ryygnrm 1 1104mm Tfi Elm? Kdn mus (M60542 05- l wfdu PATENTEUHARZYISB SHEET 2 OF 3 FiGZ IWew run I UNI/56H 74:03? anusr KUME'R IMAM #46 1 71 INDUSTRIAL FURNACE BACKGROUND OF THE INVENTION The present invention relates to industrial furnaces in general, and more particularly to a regenerative industrial furnace, especially a regenerative coking oven battery.

It is well known and requires no detailed discussion that many attempts have been and are being made to increase the throughput of coking ovens. This includes, by way of example, the various attempts at equalizing the coking coal, in particular with reference to the water content thereof, and the regulation of heating capacity by constant supply of elevated temperature. It is also known to attempt an improvement of the desired character by increasing the temperature of the heatexchange walls of such ovens and the utilization of densified masonry material.

Tests and observations have indicated that when the supply of heat to the coking chamber is uniform over the entire height thereof during the coking period, the temperature in the upper third of the furnace will lag behind significantly and the desired temperature profile that is temperature distribution over the height of the coking chamber, is achieved only towards the end of the coking period. Detailed tests have shown that the reason for this is the more rapid de-gasing of the coal in the lower portion of the coking chamber, leading based upon the availability of heat in the upper portion of the chamber which is too small to condensation of water vapors and degasification products. It has already been proposed to overcome this difficulty in that the furnace chamber is so heated that with reference to the temperature of the charge in the median region of the height of the furnace chamber, the temperature in the lower region of the furnace chamber is less by approximately 50- 150 C., whereas the temperature in the upper region of the chamber is at least approximately 100 C. higher. This graduated heating is to be achieved in that the wall thickness of the wall bounding the furnace chamber decreases in upward direction of the latter, or that in the upper region of the walls bounding the height of the furnace chamber masonry material is utilized having a better thermal conductivity than the material used in the lower region. In fact, this proposal has led to an improvement but optimum coking of the coal has been incapable of being achieved therewith. It has been found that this optimum result can be achieved only by individually heating, and regulating the temperature of, the individual chambers. However, the existing regenerative furnace systems invariably do not make it possible to individually heat the lateral walls bounding the coking or furnace chamber of opposite sides thereof. A proposal which has been made, to combine several furnaces, for instance five of them, to a group which are filled, heated and emptied in almost identical time periods, has also been found to be less than satisfactory.

SUMMARY OF THE INVENTION It is, accordingly, an object of the present invention to overcome the aforementioned disadvantages.

More particularly, it is an object of the present invention to provide an industrial furnace, especially a regenerative furnace for coking purposes which overcomes these problems.

In pursuance of the above objects, and of others which will become apparent hereafter, one feature of the invention resides in providing, an industrial furnace of the type under discussion, wall means which defines at least one furnace chamber on opposite sides and at least two hollow heat-exchange walls each located at and proximal to one of these sides for exchanging heat with the furnace chamber. At least two regenerators are provided each of which communicates with one of the heat-exchange walls, and means are provided for alternately feeding air and flue gas to these regenerators.

In this manner, the heating of both walls bounding the furnace chamber at opposite sides thereof can be programmed, that is both walls can be individually heated in accordance with a desired program or profile, and the chamber and the contents thereof can be supplied at proper times with precisely the requsite temperature, whereas the supply of heat energy can be selectively and at the proper time be terminated when the coking process is completed.

The invention can be utilized both in under-fired furnaces as well as in top-fired furnaces and irrespective of the manner in which the heat energy is supplied.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in con nection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic fragmentary vertical section illustrating one embodiment of the invention;

FIG. 2 is a fragmentary top-plan view of FIG. 1; and

FIG. 3 is a view similar to FIG. 1 but of another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing in detail and firstly FIGS. 1 and 2 thereof, it will be seen that this illustrates a so-called twin-draft furnace which can be under-fired or top-fired. In FIG. 1 the furnace is under-fired and in conventional constructions the furnace chambers l of which several are provided and which accommodate the coal to be coked will be separated from one another by single heat-exchange walls each of which is provided with a plurality of upright hollow passages for heat-exchange medium. According to the embodiment as shown in FIGS. 1 and 2, however, the single heatexchange wall of the conventional constructions is replaced by two heat-exchange walls 2 and 3 which are located at opposite lateral sides of each furnace chamber 1. Reference numeral 10 indicates masonry between these walls, and it will be appreciated that each wall 2 is adjacent the wall 3 of the laterally next adjacent furnace chamber 1. These heat-exchange walls 2 and 3 each associated with one of the furnace chambers 1 are provided, as is especially clear from a comparison of FIGS. 1 and 2 with a plurality of upright passages through which heat exchange fluid can flow in the direction of the arrows indicated in FIG. 1.

Located below the chambers l and the heatexchange walls, are regenerators 4 and 5 of conventional construction and in the illustrated embodiment each regenerator 4 is connected with one of the heatexchange walls 2 and each regenerator 5 is connected with one of the heat-exchange walls 3. Previously, that is in the prior art, only a single regenerator was provided feeding the single heat-exchange wall located between laterally adjacent chambers 1.

Reference numeral 6 identifies conduits which connect the regenerators with the respectively associated heat-exchange walls, and reference numeral 7 identifies gas supply conduits which are connected via con duits 8 with the respective heat exchange walls 2 and 3. Reference numeral 9 identifies channels which communicate with the regenerators 4 and 5 for supplying to them the requisite air, and also for withdrawing flue gases from the regenerators.

With the construction according to the present invention heat energy can be supplied much more precisely and selectively to the contents of the respective chamber 1, in that heat can be supplied via the heat exchange wall 2 associated with the chamber, via the wall 3 associated with the chamber, or via both. The regenerators are of course of known construction and it is not believed necessary to discuss them in more detail, inasmuch as the concept of the invention lies not in the manner in which the heat energy is generated, but in the manner in which it is supplied to the respective chamber 1.

The embodiment of FIG. 3, in which like reference numerals identify components as in FIGS. 1 and 2, differs from FIGS. 1 and 2 in showing a different furnace in which during one heating period half of the heat exchange walls is subjected over half of their respective overall height to the action of flames, with the flue gases or combustion gases leaving through a channel located above the heat-exchange walls and flowing downwardly back to the regenerators through the other heat exchange walls, that is the heat exchange walls which are not being heated during this period. After such a heating period is completed, the flow direction of the hot gases is reversed, and consequently, each of the regenerators alternately receives air and flue gases in alternating heating periods.

Such furnaces may also be under-fired or top-fired, and what is essential is that here as in the embodiment of FIGS. 1 and 2, each of the chambers 1 again has associated therewith two heat exchange walls located at opposite lateral sides thereof.

By resorting to the present invention the control of temperature in the chambers 1, and thereby the control of temperature in the charge in these chambers, is facilitated and the advantageous results indicated above as desirable are obtained.

It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in an industrial furnace, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

We claim:

1. In an industrial furnace, particularly a regenerative furnace, wall means defining at least two laterally adjacent furnace chambers each having opposite sides, and at least two pair of heat-exchange walls having hollow unconnected interiors, the walls of each pair being located at and proximal to the respective sides of each furnace chamber for exchanging heat with said respective furnace chamber; a plurality of regenerators communicating with respective ones of said heat-exchange walls so that each of said walls can be heated independently of the others; and means for alternately feeding air and flue gas to said regenerators.

2. In an industrial furnace, as defined in claim 1, wherein each of said heat-exchange walls extends along a respective side of one of said chambers and is provided with a plurality of internal passages communicating with one of said regenerators.

3. In an industrial furnace as defined in claim 2, wherein said chambers each have a top and a bottom, and wherein said passages extend in direction from said top to said bottom. 

1. In an industrial furnace, particularly a regenerative furnace, wall means defining at least two laterally adjacent furnace chambers each having opposite sides, and at least two pair of heat-exchange walls having hollow unconnected interiors, the walls of each pair being located at and proximal to the respective sides of each furnace chamber for exchanging heat with said respective furnace chamber; a plurality of regenerators communicating with respective ones of said heat-exchange walls so that each of said walls can be heated independently of the others; and means for alternately feeding air aNd flue gas to said regenerators.
 2. In an industrial furnace, as defined in claim 1, wherein each of said heat-exchange walls extends along a respective side of one of said chambers and is provided with a plurality of internal passages communicating with one of said regenerators.
 3. In an industrial furnace as defined in claim 2, wherein said chambers each have a top and a bottom, and wherein said passages extend in direction from said top to said bottom. 